Out of curiosity, how much does it typically cost to charge, say, an iPhone5? For some (many?) doubling this price might not be as much of a non-starter as you think.
No clue how efficient typical USB charging is, the AC-DC conversion is at around 80%, then you've got the battery chemistry which cursory research seems to peg at around 80% efficiency as well. So lets say it's about 1c per charge, at EU power prices.
Still, multiplying the cost of charging an iPhone by 10 isn't bad. And in fact you can buy a lot of solutions that enable this, because you're right, it's not a big deal for a lot of people, and the convenience is worth the cost.
For an electric car, increasing the charging cost by a factor of 10, or even a factor of 2, is a much tougher proposition.